Michael Hermosillo's RBI single in the seventh inning provided the deciding run and rookie Hayden Wesneski pitched an immaculate inning Thursday as the visiting Chicago Cubs downed the Pittsburgh Pirates 3-2.

Christopher Morel added a two-run double for the Cubs (65-85), who won for the seventh time in 10 games.

Wesneski (2-1), making his second career start and fourth appearance, pitched 6 1/3 innings, allowing two runs and five hits with six strikeouts and two walks.

The right-hander pitched an immaculate inning in the fifth, striking out Jack Suwinski, Zack Collins and Jason Delay on nine pitches. According to the team, Wesneski became the first Cubs pitcher to complete an immaculate inning since LaTroy Hawkins on Sept. 11, 2004, against the Marlins.

Mark Leiter Jr. got seven outs to record his third save of the season.

Kevin Newman homered and Bryan Reynolds was 3-for-3 with two doubles and two walks for the Pirates (55-95), who have lost seven straight.

Pittsburgh starter Mitch Keller (5-12) gave up two runs and four hits in six innings. He struck out seven strikeouts and walked two.

In the second inning, Chicago's David Bote hit a leadoff single to center. After a flyout and a strikeout, Hermosillo singled to right, with Bote going to second. Morel brought them both home with a double to left for a 2-0 Cubs lead.

Pittsburgh cut it to 2-1 in the third. Delay drew a one-out walk and went to second on Oneil Cruz's groundout. Reynolds followed with a single to right, driving in Delay.

All-Star closer David Bednar, just off the IL after recovering from a back injury that had kept him out since late July, came on for Pittsburgh in a different role, in the seventh.

Alfonso Rivas lined Bednar's first pitch up the middle for a single. As Nelson Velazquez struck out, Rivas stole second. Hermosillo singled to left-center to drive in Rivas for a 3-1 Chicago lead.

The Pirates sliced into that in the bottom of the seventh when Newman hit his second homer, down the line in left, to make it 3-2.

Leiter hit a batter and walked a batter in the ninth but got Rodolfo Castro to line out to center field for the final out.